Body and fender tool



3l E95@ H. P. HARTMAN BODY AND FENDERTOOL Filed May 22, 1947 IIIIIIIIIII- Illllllllllll 4Widespread use.

Patented Oct. 31, 1950 UNITED Y STATES PATENT OFFICE This invention relates to body and fender tools, particularly to pneumati-cally operated tools of this type which include opposed members adapted to engage the opposite faces of an intermediate metal sheetand at leastl one of which is adapted to be vibrated at high frequency.

Tools of this general type and suited for use in straightening and smoothing bent or crumpled automobile fenders or body panels are now in In each instance such a tool includes opposed work engaging members, com- .fmercially known as dollies, together with a frame upon which the dollies are mounted and 'upon which is supported a means for effecting the vibration at relatively high frequencyl of at least one of the dollies, the moving dollybeing in the nature of a hammer,=delivering blows of 'low amplitude 'but high frequency against the Work, and the opposed dolly being inthe nature -found necessary, after a sheet such as an automobile fender has been subjected to the action of such a tool, to smooth that surface which is to be subsequently painted with a file prior to the actual application of the paint or enamel. This is because the vibrating dolly, even when most skillfully used, leaves fiat imprints upon the metal being treated and, even though these flat imprints are of relatively small area individually, they may, nevertheless, be observed even after the application of paint, thus necessitating the vuse of an abrading tool to produce a smooth rounded surface which will have the appearance of one which has not been injured. Prior ktools of this general nature have likewise been deficient in that even the best of them will occasionally catch against a protuberance on the surface over which it is moved and will sometimes put nicks in the sheet metal being straight- Aened and smoothed. Fender tools of the prior art have also been so designed and constructed that fairly satisfactory results may be obtained only after the operator has had longv experience in its use, rather poor results being obtained ,when the tool is in the hands of anoperator without such experience. x

'Ihe improved body and fender tool, a pre- -straightening force exerted` thereon.

ferred embodiment ofrwhich is illustrated in the accompanying drawings and will be hereafter described in detail, has a substantially improved ability to work damaged metal sheets into desired contour and surface smoothness. Two opposed dollies are provided, ras heretofore, but one of them, preferably the vibrating dolly, is so designed and constructed that its work engaging face is discontinuous and comprises, instead of a smooth flat or gently rounded surface, a plurality Vof spaced, relatively small, rounded work engaging elements adapted to simultaneously strike the face of the metallicsheet to be straightened and to be simultaneously lifted from the surface of the work when the direction of the movement of they dolly is reversed. A sheet intermediate the opposed dollies, upon being struck simultaneously by a substantial number of the rounded work engaging elements of the moving dolly, will .be beneficially worked over a considerablev area and the necessary At the same time the effect upon the sheet is materially different from the veffect realized when a dolly of the prior art is in use, each impact-leaving a regular seriesof spaced rounded shallow indentions in the metallic surface instead of a single, relatively large and generally flat surface as heretofore. i

Y It is found that a body yand fender tool employing a dolly of the improyed type above briefly described will remove creases in the ycrumpled metal in a superiormanner, is more effective in the lifting of low spots in the metal and bringing all areas thereof to the desired contour and that, as `a result of its user large areas of damaged or crumpled metallic sheet may beso perfectly restored to its original ,contour as to be ready for the application of paint immediately upon the completion of the shaping operation, no further ymechanical preparation of the surface for Athe receptionof paint,'as by ling, being necessary.

The improved tool will not put nicks in the metal .being subjected to its action and may -be moved readily and vrapidly over its surface without catching. It is of mostY durable nature and may be readily kept in perfect operating Icondition.

ous work engaging surface, a series of hardened y steel balls, such as ball bearings, and in one form of the invention primarily intended for use in the lstraightening ,of fenders and automobile body acter as to be readily applicable to the standard body and fender tool. Means is provided for facilitating the cleaning of the tool and, in the preferred embodiment of the invention, ductsI passing entirely through the body have their inlet ends in communication with the recesses, respectively, in which the hardened ste el balls are housed. After the dolly has been in usel for some time fluid, such as compressed air or a cleaning solution, may be forced Vthrough the dollyr, being preferably first passed through the several ball receiving recesses, which are not completely blockedl by the balls which they contain, and thereafter passing through ducts or conduits leading from these recesses to discharge ports in opposite faces of the body.` The specific details of design may be changed in variousiways without departure from the invention but I prefer to employ dollies of the type described, comprising p hardened steel balls and suitable means for retaining them in spaced' relation upon the body of the dolly so. that thev together constitute a series of rounded work engaging elements which. constitute a discontinuous work engaging surface.`

In some instances, however, the rounded work engaging elements may be formed integral with the body of the dolly; ^Itl is possible to utilize various styles of separately formed work engaging elements and to secure them to the body of the dolly in various ways;

In the' drawings, in which there Vis illustrated a preferred form of the invention by way of` example,

Figure l illustrates in section a small portion of a metal sheet to be straightened and shows in side elevation the opposed dollies which comprise the work engaging members; Y

Figure 2 is an enlarged vview of the face of the vibratory dolly, portion of the cap being broken away so that the face of the body of' the'.dolly may be clearly perceived;

Figure 3 is a section on line 3 3 of Figure 2;

Figure 4 is an enlarged section through por'- tion of the dolly, showing a few of the work engaging elements and more clearly disclosing adjacent portions of cap and body.

Figure 5 is a view generally similar to Figure 2 showing the rear of a modified form of the dolly; and

Figure 6 is a section on linev 6-6 of Figure 5'.

The body of the dolly illustrated i'n'Fgures 1 to 4 inclusive includes a forward portion in the nature of an annular disc il! and a stern I I which is generally cylindrical in shape, the stem and disc Ii] being preferably formed from one piece of metal. The forward face of the disc Il! is provided with a concentric series of annular grooves l2, I3, I 4, I5, I6 and I'l'respectively and the lands or circular ridges intermediate these grooves comprise seating Vmembers against which the -work impacting elenr-ier-itsV are adapted to rest.

The work engaging. elements are, inthe form of the invention disclosed, hardenedsteel balls I8 and these balls are disposed in concentric rings as clearly shown in the drawings, with a single ball Ia occupying the central position and engaging the central ball supporting land, which is encircled by the annular groove I2.

The balls are retained in the positions in which they are shown by means of a cup shaped member or cap 2i) which is provided with a plurality of ball receiving recesses, several of which are most clearly shown in Figure 4 and indicated at 2|. The diameterof .each opening` 2 I at the rear face of the cap` and for approximately half of its length is slightly greater than the diameter of `the ball which is housed therein but' each recess, as may be clearly observed in Figure 4, has a forwardly and outwardly tapering spherical socket portiony 2m which terminates in a circular opening 2lb formed in the forward face of the cap. The thickness of the cap is such that, when it is-positioned as shown in Figures 3 and 4, each ball will be retained in a ball receiving recess which is just suiciently large to provide a snug housing for the ball; which may not escape nor move materially, being laterally coni-ined by the circular Vwall of the recess, -prevented from moving forwardly because of its engagement with the spherical retaining surface Zia, and mayy not move rearwardly because of its engagement with the surface of the associated land of the body of the dolly. Because of the fact that the diameter of each ball is slightly less than the diameter of the recess in which it is` received, the ball may turn when the instrument is in use. The slight clearance between each ball and the wall of the recess in which itis confined also permits fluid under pressure to be forced through the several apertures in the face of the cap and around the ball and into the adjacent grooves, for instance grooves Ill and I5 shown in Figure 4, from which grooves the uid may pass into ducts, such as indicated at 22', andr led to the rear facesv of disc I0 and stem l! ofthe dolly. Suitable means for forcing liquid or gas under pressure may be provided and a cleaning operation may be effected very quickly in this mannenaliquidlsolvent being passed through Vthe dolly in the'event that the ball receiving recesses contain grease or other soluble material which might tendto interfere with the freedom of movement of the balls` The invention contemplates they utilization of dollies in which the discontinuous `work engaging surfaces are not-only flat, as disclosed in Figures 1 to 4 inclusive, but convex, a dolly having a convex discontinuous work engaging surface being shown in Figures 5 and 6. In this form of the invention the active face of the dolly is elongated, being preferably oval in shape, and the axis of the stem II is offset from the axis of the integral duct portion |01 of the dolly. The ball retaining cap 291 is convex, as' illustrated, but the several balls are retained as before in recesses defined in part by the cap and in part by the lands intermediate grooves |21, I31, 141 and |51 formed Ain the convex forward face lill of the body. A dolly so formed with discontinuous convex surfaces, is* particularly suitable for use in the straightening of fenders which have been seriously damaged and the dolly in such use may be tilted to various angles as it is advanced over the work. Other forms of the invention may be devised to suit special circumstances.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A dolly for a body and fender tool adapted to be vibrated at high frequency when in contact with a sheet metal member to be smoothed, said dolly having a ball supporting base and a ball retaining and spacing cap secured to the base in ball retaining position, portions of the balls extending beyond the cap to form a discontinuous metal working surface, and ducts formed in and passing through the said base to communicate with the ball receiving recesses, whereby fluid under pressure may be forced into said recesses. y

2. A dolly of the class described comprising a base having a plurality of seating surfaces for a plurality of hardened steel balls disposed substantially in a plane, and a perforated cap secured to the base, the balls being confined by the cap and seating surfaces of the base, a portion of each ball projecting through a perforation in the cap and the several such projecting portions together comprising a discontinuous work engaging surface, the said base being provided with a plurality of ducts passing entirely therethrough, one end of each duct opening into the ball conning space, whereby fluid under pressure may be forced into the said recesses.

HAROLD P. HARTMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS' Number Name Date 681,964 Hurst Sept. 3, 1901 921,739 Rieske May 18, 1909 1,058,856 Gibbs Apr. 15, 1913 1,148,131 Thompson July 27, 1915 1,196,942 Fraser Sept. 5, 1916 1,549,187 Claybourn Aug. 11, 1925 1,718,425 I-Iilstad June 25, 1929 FOREIGN PATENTS Number Country Date 311,983 Italy Oct. 17, 1933 

